Update libvpx snapshot to v0.9.7-p1 (Cayuga).

source/libvpx/configure

Index: source/libvpx/configure
===================================================================
--- source/libvpx/configure	(revision 96967)
+++ source/libvpx/configure	(working copy)
@@ -31,14 +31,16 @@
   ${toggle_md5}                   support for output of checksum data
   ${toggle_static_msvcrt}         use static MSVCRT (VS builds only)
   ${toggle_vp8}                   VP8 codec support
-  ${toggle_psnr}                  output of PSNR data, if supported (encoders)
+  ${toggle_internal_stats}        output of encoder internal stats for debug, if supported (encoders)
   ${toggle_mem_tracker}           track memory usage
   ${toggle_postproc}              postprocessing
   ${toggle_multithread}           multithreaded encoding and decoding.
   ${toggle_spatial_resampling}    spatial sampling (scaling) support
   ${toggle_realtime_only}         enable this option while building for real-time encoding
+  ${toggle_error_concealment}     enable this option to get a decoder which is able to conceal losses
   ${toggle_runtime_cpu_detect}    runtime cpu detection
   ${toggle_shared}                shared library support
+  ${toggle_static}                static library support
   ${toggle_small}                 favor smaller size over speed
   ${toggle_postproc_visualizer}   macro block / block level visualizers
 
@@ -152,6 +154,7 @@
 enable install_bins
 enable install_libs
 
+enable static
 enable optimizations
 enable fast_unaligned #allow unaligned accesses, if supported by hw
 enable md5
@@ -211,6 +214,7 @@
     alt_tree_layout
     pthread_h
     sys_mman_h
+    unistd_h
 "
 CONFIG_LIST="
     external_build
@@ -240,7 +244,7 @@
     runtime_cpu_detect
     postproc
     multithread
-    psnr
+    internal_stats
     ${CODECS}
     ${CODEC_FAMILIES}
     encoders
@@ -248,7 +252,9 @@
     static_msvcrt
     spatial_resampling
     realtime_only
+    error_concealment
     shared
+    static
     small
     postproc_visualizer
     os_support
@@ -281,14 +287,16 @@
     dc_recon
     postproc
     multithread
-    psnr
+    internal_stats
     ${CODECS}
     ${CODEC_FAMILIES}
     static_msvcrt
     mem_tracker
     spatial_resampling
     realtime_only
+    error_concealment
     shared
+    static
     small
     postproc_visualizer
 "